Suction accumulator for refrigeration systems



Jan. 6, 1970 'H. C. WAGNER Masma SUCTION ACCUMULATOR FOR REFRIGERATION SYSTEMS Filed May 3, 1968 I w vE M TOR r lmwm c. mama? United States Patent 3,488,678 SUCTION ACCUMULATOR FOR REFRIGERA- TION SYSTEMS Harry C. Wagner, Newark, N.Y., assignor to Parker- Hannifin Corporation, Cleveland, Ohio, a corporation of Ohio Filed May 3, 1968, Ser. No. 726,355 Int. Cl. F25b 43/00 US. Cl. 62-503 5 Claims ABSTRACT OF THE DISCLOSURE A suction accumulator for a refrigeration system with means to prevent delivery of liquid to the compressor intake. The accumulator comprises a tank having an inlet for receiving refrigerant fluid in vaporized form but which may include slugs of liquid, and has an outlet at its upper end for delivering the vapor to a compressor, and there being a tube in the tank with an open end to receive the vapor at the tank inlet and having a closed end and a transverse opening near the tank outlet whereby any slugs of liquid in the tube are prevented by the closed end from reaching the tank outlet and are diverted through the transverse openings so as to drop to the tank bottom.

BACKGROUND OF THE INVENTION Suction accumulators are used in refrigeration systems to receive vaporized refrigeration fluid from the system for recirculation by the compressor. The fluid coming into the accumulator may be only partially vaporized and thus be partially in liquid form. Also, condensation of the vapor occurs within the tank during periods that the system is not in operation and likewise occurs to some extent during operation. In addition, it is desirable that oil be circulated with the refrigerant fluid for lubricating the compressor and other moving parts in the system. Thus, oil as well as refrigerant fluid is likely to be present in liquid form in the tank at all times.

It is important that the accumulator deliver fluid only in vapor form to the compressor because intake of liquid therein would quickly cause extensive damage to the compressor.

SUMMARY OF THE INVENTION The invention provides a means to assure that only vaporized fluid is delivered to the compressor. This is accomplished by providing an outlet at the top of the tank for connection to the compressor intake and by pro viding a tube with a closed end within the tank to receive incoming fluid and discharge it into the tank through transverse openings near the closed end. .The tube may be generally U shaped with the bottom of the U in the lower portion of the tank and with the legs extending to the upper portion of the tank. One leg has an open end to receive the fluid and the other leg has a closed end but has trasverse openings near the closed end through which the incoming fluid discharges from the tube into the tank in a direction away from the outlet. Any liquid discharging through the transverse openings will either vaporize or drop in liquid form to the bottom of the tank whereby only vapor will pass through the tank outlet.

The tube includes a metering orifice near the bottom of the tank. When the system is not in operation liquid within the tank enters the tube through the orifice and fills the tube to the level of liquid within the tank. Upon startup, the liquid within the tube is forced rapidly toward the closed end but the latter prevents it from being impelled into the tank outlet and the liquid discharges 3,488,678 Patented Jan. 6, 1970 sidewardly from the tube and falls to the tank bottom. During operation, liquid oil enters the tube through the orifice at a metered or restricted rate and is vaporized therein and mixed with the refrigerant vapor for discharge to the compressor.

BRIEF DESCRIPTION OF THE DRAWING The drawing shows the accumulator in vertical cross section.

DESCRIPTION OF THE INVENTION In the illustarted embodiment, the accumulator in cludes a cylindrical tank 10 with an outlet opening 11 at the top into which a discharge tube 12 leading to the intake side of a compressor (not shown) is sealingly mounted by brazing or other means.

U-tube 15 has one leg 16 that enters the tank through an opening near in the upper portion of the latter and is sealed relative thereto by brazing or the like. The end of leg 16 that projects from the tank is for connection to the discharge side of the evaporator, which is not shown. The bottom 17 of the U-tube is in the lower portion of the tank and has an orifice 18. The other leg 19 of the U-tube extends toward the top of the tank and has a closed end 21 spaced upwardly of one or more transverse openings 22. The inner end 23 of discharge tube 12 preferably extends somewhat below curved inner wall 25 of the tank. The outer end of tube 12 connects to the intake side of the system compressor, which is not shown.

OPERATION When the refrigeration system is not in operation, the tank will contain some liquid at its lower end which may be oil alone or a mixture of oil and liquid refrigerant fluid. The liquid will have entered tube 16 through orifice 18 so that it will have filled both legs of the U-tube to a level equal to that of the liquid in the tank. The remainder of the tank and tube spaces will be filled with refrigerant fluid vapor.

Upon starting the system, the compressor will start drawing vapor from the tank through. discharge tube 12 and reduce the pressure in the tank vapor space so that liquid within tube 15 will move rapidly upward in leg 19 but closed end 21 will cause the liquid to discharge laterally from leg 19 through transverse openings 22. As the liquid discharges from openings 22 it impinges upon the side wall of tank 10 and drops to the tank bottom. Thus no liquid is discharged from leg 19 in a direction to permit it to enter discharge tube 12. Also, any liquid that might be splashed or drawn upwardly along the inner surface of the tank upper portion will impinge against the exterior surface of discharge inner end 23 and drop to the bottom of the tank.

As the refrigeration system continues in operation and the liquid initially within tube 15 is either vaporized or returned to the tank through openings 22, additional liquid is metered into the tube through orifice 18. This additional liquid vaporizes within the tube and mixes with the refrigerant vapor therein for discharge to the tank and then through discharge tube 12 to the compressor.

As operation of the system continues, the refrigerant fluid entering tube 15 from the evaporator is normally in vaporized form but occasionally may include some liquid. In the latter case, the liquid moves from leg 16 to leg 19 and because of close end 21 of the latter is discharged laterally through transverse openings 22 and drop to the bottom of the tank whereby only vapor will pass out of the tank through discharge tube 12.

I claim:

1. A suction accumulator for receiving liquid and vapor fluids from a refrigerating system and discharging only vapor to the system comprising a tank having an outlet opening in the upper section thereof for discharging vapor from the tank to the system and having an inlet opening for receiving said fluids from the system, a tube within the tank extending from a lower section thereof toward said upper section, the lower portion of the tube communicating with said inlet opening, the upper portion of the tube having a closed end and a transverse opening below said outlet opening whereby liquid and vapor entering the tube at said inlet opening passes through said transverse opening into the tank, said transverse opening being positioned so that liquid discharging through the transverse opening is directed away from the outlet opening.

2. The accumulator of claim 1 in which a discharge tube extends through the outlet opening and has an inner end that extends below the adjacent portion of the tank wall.

3. The accumulator of claim 1 in which a discharge tube extends through the outlet opening and has an inner end that extends below the adjacent portion of the tank wall and opens downwardly in the tank.

4. The accumulator of claim 1 in which said inlet opening is in said upper tank section, and offset from the vertical axis of the tank said tube is generally U shaped with one leg projecting through said inlet opening to said tank lower section and the other leg of the U extends from the tank lower section to the tank upper section and oflset from the vertical axis of the tank substantially the same amount as said one leg, and said other leg having said closed end and said transverse opening, said transverse opening being vertically spaced from said tank utlet opening, and said outlet being centrally located in the top wall of the tank.

5. The accumulator of claim 4 in which said transverse opening is vertically spaced from said closed end.

References Cited UNITED STATES PATENTS 2,787,135 4/1957 Smith 62-503 3,212,289 10/1965 Bottum 62-503 MEYER PERLIN, Primary Examiner 

